Dosimetric comparison of intensity-modulated radiation therapy (IMRT) and intensity-modulated proton therapy (IMPT) for a novel oral tongue avoidance concept in low-risk squamous cell carcinoma of the oral tongue Journal Article

   

Authors:	Press, R. H.; Hu, L.; Huang, S.; Hasan, S.; Choi, J. I.; Simone, C. B. 2nd; Chhabra, A. M.; Gelblum, D. Y.; Kabarriti, R.; Bakst, R. L.; Cracchiolo, J. R.; McBride, S. M.; Lee, N. Y.
Article Title:	Dosimetric comparison of intensity-modulated radiation therapy (IMRT) and intensity-modulated proton therapy (IMPT) for a novel oral tongue avoidance concept in low-risk squamous cell carcinoma of the oral tongue
Abstract:	Purpose: After adequate surgical resection, early-stage oral tongue cancer patients can harbor a low risk of local recurrence but remain at risk of regional recurrence. Oral tongue avoidance during adjuvant radiation therapy is an attractive potential treatment strategy to mitigate treatment toxicity. We sought to quantify the dosimetric advantages of this approach and hypothesized that intensity-modulated proton therapy (IMPT) may further reduce organs at risk doses compared with intensity-modulated radiation therapy (IMRT). Materials and Methods: Five patients with oral tongue cancer treated with postoperative radiation therapy from August 2020 to September 2021 were retrospectively reviewed. Novel clinical target volume contours, excluding the oral tongue, were generated while maintaining coverage of bilateral at-risk lymph nodes. Comparison IMRT (X) and IMPT (PBT) plans were generated using standard treatment volumes (control) and avoidance volumes (study) (n = 4 plans/patient). Dosimetric variables for organs at risk were compared using the paired t test. Results: The prescribed dose was 60 Gy in 30 fractions. D95% clinical target volume coverage was similar between X and PBT plans for both control and study clinical target volumes. Comparing control with study plans, both X (58.9 Gy vs 38.3 Gy, P = .007) and PBT (60.2 Gy vs 26.1 Gy, P < .001) decreased the oral cavity dosemean. The pharyngeal constrictor dosemean was also reduced (P < .003). There was no difference between control and study plans for larynx (P = .19), parotid (P = .11), or mandible dose (P = .59). For study plans, PBT significantly reduced oral cavity dosemean (38.3 Gy vs 26.1 Gy, P = .007) and parotid dosemean (23.3 Gy vs 19.3 Gy, P = .03) compared with X. For control plans, there was no difference in oral cavity dosemean using PBT compared with X, but PBT did improve the parotid dosemean (26.6 Gy vs 19.7 Gy, P = .02). Conclusion: This study quantifies the feasibility and dosimetric advantages of oral tongue avoidance while still treating the at-risk lymph nodes for oral tongue cancer. The dosimetric difference between PBT and X was most prominent with an oral tongue-avoidance strategy. Copyright © 2023 The Author(s)
Keywords:	oral cavity; proton therapy; dosimetric analysis; oral tongue
Journal Title:	International Journal of Particle Therapy
Volume:	9
Issue:	4
ISSN:	2331-5180
Publisher:	Particle Therapy Cooperative Group
Date Published:	2023-01-01
Start Page:	253
End Page:	260
Language:	English
DOI:	10.14338/ijpt-22-00032
PROVIDER:	scopus
PMCID:	PMC10166015
PUBMED:	37169010
DOI/URL:	https://www.scopus.com/inward/record.uri?eid=2-s2.0-85175181790&doi=10.14338%2fIJPT-22-00032&partnerID=40&md5=dd077726b8814bc5b514ba55bd9482a1
Notes:	Article -- The PDF lists the publication date as Spring issue -- Source: Scopus

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